automate a plane to look at camera

Hi, maybe this is a dumb question but I'm trigonometry ignorant and I've got a problem:
I'd like to make some planes automatically oriented to the camera, as you can see from the patch I use two textured planes to make some flare light effect, now, if I move the camera the trick becomes evident, so I thought that if I make the planes always oriented to the camera the trick is still efficient. Can you put me on the right way to do this?
It takes a lot to me make those light travel on a sphere path like and I really don't know where to start to make them always oriented to the camera.
In attached you can find the png file for the "flare effect"

Sorry for my bad English and thanks a lot for your attention.

– Pasted Max Patch, click to expand. –

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maybe you could use a sphere instead of a plane , and find the good shader .
the "mat.phong.glsl.jxs " one , present in Max6/Cyclin’74/Jitter Shaders/Material
seems to do the job quite well (setting the param "la" to -0.4 , then tweak the rest )
maybe you’ll find it good .
you wouldn’t have to care for the planes’ orientation anymore .
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